1. Field of the Invention
The invention generally relates to a lamp driving apparatus and a level shift driving circuit.
2. Description of Related Art
FIG. 1 is a schematic circuit diagram of a conventional fluorescent lamp driving circuit. A ballast controller 10 includes a high side driving circuit HSD and a low side driving circuit LSD which respectively drive a high side P-type MOSFET M1 of a switch module 40 via a high side driving pin OUT 1 and a low side N-type MOSFET M2 of a switch module 40 via a low side driving pin OUT2. The high side P-type MOSFET M1 and the low side N-type MOSFET M2 are connected with each other between an input power source VIN and a ground. The ballast controller 10 controls the high side P-type MOSFET M1 and the low side N-type MOSFET M2 to transmit power of the input power source VIN into a resonant module 30. The resonant module 30 includes an inductor L1 and a capacitor C2 to convert the power of the input power source VIN into an AC output signal so as to drive a lamp 20.
In order to ensure that the high side P-type MOSFET M1 and the low side N-type MOSFET M2 are indeed turned on or off, both of the high side driving circuit HSD and the low side driving circuit LSD require being connected between the input power source VIN and the ground simultaneously. However, because the driving voltage of the lamp 20 is several hundreds of volts, the voltage of the input power source is also in the order of hundreds of volts as well. Thus, the ballast controller 10 is required to be produced with a high voltage process, such that the process of fabricating the ballast controller 10 is difficult and the manufacturing cost thereof is increased.